The present invention relates to a pattern forming method and apparatus which allows a desired pattern to be formed on a substrate implementing a large-scale panel such as a PDP (Plasma Display Panel), liquid crystal panel, organic EL (Electro Luminescence) panel, or circuit board with a low cost, and yet which allows a fine pattern to be formed with high precision. The invention also relates to pattern-forming material particles to be used for the pattern forming method and apparatus.
PDPs have become far thinner than CRT type image display devices, and flat in their image-displaying surfaces, thus being considered as useful for so-called wall-hanging type large-scale image display devices or the like.
In the image display mechanism of a PDP, in which a micro-cell structure is formed between a pair of transparent glass plates, plasma arcs are generated by this cell structure so that a fluorescent layer formed within the cell structure emits light, the resulting light emission being allowed to penetrate through the transparent glass plates so as to be radiated outside. In this one pair of glass plates, a multiplicity of transparent linear electrodes intersecting one another are formed, and producing plasma emission at the intersecting points of those linear electrodes allows an emission image having any arbitrary pattern to be formed. Arranging fluorescent layers corresponding to the three primary colors of R, G and B enable the display of color images.
Now, an explanation of PDPs is given below.
As shown in FIG. 85, a plasma display panel (PDP) is so constructed that electric discharge is generated locally between opposing two substrates, i.e. a front glass plate 80 and a back glass plate 89, thereby causing fluorescent layers 85 formed in partitions on the substrate to be excited so as to emit light.
On the inner surface of the front glass plate 80, transparent electrodes 81 for generating surface discharge along the substrate surface are arrayed, by one pair for each line. Each of the transparent electrodes 81 comprises a wide, linear band-shaped transparent electrode made of ITO thin film, and a narrow, linear band-shaped Ag bus electrode 82 made of metal thin film. The bus electrode 82 is an auxiliary electrode for ensuring appropriate electrical conductivity. A dielectric layer 83 is provided so as to cover the transparent electrodes 81, and a protective film 84 of MgO is deposited on the surface of the dielectric layer 83. Both the dielectric layer 83 and the protective film 84 have light transparency.
Next, on the inner surface of the back glass plate 89, address electrodes (data electrodes) 88 are arrayed so as to perpendicularly intersect the transparent electrodes 81. One linear rib, indicated by numeral 86, is provided between every adjacent ones of the address electrodes 88. The ribs 86 are formed from low melting-point glass, and opaque to ultraviolet rays. These ribs 86 partition the discharge space along the line direction in sub-pixels (unit light-emitting areas), and define the gap size of the discharge space.
Then, the fluorescent layers 85 of the three colors of R, G and B for color display are provided so as to cover the back wall surface including upper portions of the address electrodes 88 and side faces of the ribs 86. The transparent electrodes 81 correspond to one line of the matrix display, and one address electrode 88 corresponds to one column. Then, three columns correspond to one pixel (picture element). That is, one pixel is made up of three sub-pixels of R, G and B arrayed along the line direction.
Stored state of wall charges in the dielectric layer 83 is controlled by opposite discharge between the address electrodes 88 and the transparent electrodes 81. Applying sustain pulses alternately to the transparent electrodes 81 causes occurrence of surface discharge (main discharge) at the sub-pixels where a specified amount of wall charges are present. Ultraviolet rays caused by this surface discharge causes the fluorescent layer 85 to be locally excited, radiating visible light of a specified color. Out of this visible light, a portion of light that is transmitted by the front glass plate 80 becomes display light. Since the arrangement pattern of the ribs 86 is a stripe pattern, portions corresponding to individual columns within the discharge space are continuous in the column direction, stretching over all the lines. The color of emission light of the sub-pixels within each column is of the same.
Because of the large size of the panel substrate, the formation of the linear electrodes onto the surface of glass plates forming the PDP has so far been implemented by screen printing process, photoetching process, and thin film process.
However, there have been issues that the screen printing process is insufficient in the precision of fine patterns, while the photoetching process and the thin film process involve large numbers of steps, resulting in high-priced pattern formation. Such issues have been applicable also to the pattern formation onto other large-scale panel substrates such as the cell-surrounding wall formation in the fabrication of liquid crystal panels or organic EL panel, or the conductor-circuit formation onto circuit boards.
In particular, in the case of techniques involving exposure and development, resulting waste liquids cannot be adopted in terms of environmental issues. Besides, exposure equipment and development equipment are large in size and large in installation site, taking high equipment costs.
Accordingly, an object of the present invention is to provide a method and apparatus for forming a pattern onto a panel substrate, the method and apparatus being simple in processes and yet good at the precision of fine-pattern formation, as well as to provide pattern-forming material particles to be used for the pattern forming method and apparatus.
In order to achieve the above objects, the present invention has the following constitutions.
According to a first aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate, comprising:
electrically charging pattern-forming material particles;
jetting out the electrically charged pattern-forming material particles through a nozzle by applying electrostatic force to the pattern-forming material particles to form a pattern; and
fixing the pattern onto the panel substrate.
According to a second aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first aspect, wherein the electrically charging is implemented by a corona charging method.
According to a third aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or second aspect, wherein in forming the pattern, a pattern is once formed on a surface of an intermediate member with the jetted out pattern-forming material particles, and thereafter the pattern on the intermediate member is transferred onto the surface of the panel substrate, by which the pattern is formed on the panel substrate.
According to a fourth aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or second aspect, further comprising performing an exposure and development process on the formed pattern.
According to a fifth aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or second aspect, further comprising: forming an adhesion layer on a surface of the panel substrate to which the pattern-forming material particles have not yet jetted out from the nozzle.
According to a sixth aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or second aspect, wherein the pattern-forming material particles are particles each having a particle size of 0.5 to 15 xcexcm formed from a compound material which contains a particle body and hard inorganic fine particles deposited on a surface of the particle body, the particle body containing one or more kinds of inorganic material selected from a group consisting of metal, metal oxide, ceramics, and glass, and a binder resin with a ratio of the inorganic material to a total amount of the inorganic material and the binder resin being 30 to 99 wt %.
According to a seventh aspect of the present invention, there is provided an apparatus for forming a pattern onto a panel substrate, comprising:
a particle feeder for feeding electrically charged pattern-forming material particles;
a nozzle placed between the particle feeder and the panel substrate; and
a jet device for jetting out the pattern-forming material particles from the nozzle by exerting an electrostatic force to the pattern-forming material particles fed from particle feeder.
According to an eighth aspect of the present invention, there is provided an apparatus for forming a pattern onto a panel substrate according to the seventh aspect, further comprising a panel substrate holder having a flat surface for holding the panel substrate, wherein the panel substrate is vacuum-sucked up by this flat surface of the panel substrate holder.
According to a ninth aspect of the present invention, there is provided an apparatus for forming a pattern onto a panel substrate according to the seventh or eighth aspect, further comprising: a detector for detecting a distance between the nozzle and the panel substrate; and a distance controller for controlling the distance between the nozzle and the panel substrate based on detection information obtained from the detector.
According to a 10th aspect of the present invention, there is provided an apparatus for forming a pattern onto a panel substrate according to the seventh or eighth aspect, further comprising, around an opening of the nozzle, an electrode for converging a jet stream of the pattern-forming material particles by applying electrostatic force to the pattern-forming material particles that pass through the opening.
According to an 11th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the first aspect, wherein the pattern-forming material particle is composed of a resin material which is to be evaporated by baking process, and a kind of constituent material particles which are disposed within the resin material at a uniform distribution and which functions to form a pattern.
According to a 12th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 11th aspect, wherein the plurality of kinds of constituent material particles which are distributed uniformly within the resin material.
According to a 13th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 11th or 12th aspect, wherein the constituent material particle has a diameter ⅕ or less a diameter of the pattern-forming material particle.
According to a 14th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 11th aspect, wherein the constituent material particle is disposed at a central portion of the pattern-forming material particle and peripherally coated with the resin material.
According to a 15th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 14th aspect, wherein another kind of constituent material particle is dispersedly disposed in the resin material present in peripheries of the central constituent material particle.
According to a 16th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 14th aspect, wherein a multiplicity of smaller-diameter resin-material particles than the constituent material particle are deposited on a peripheral surface of the constituent material particle.
According to a 17th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to any one of the 11th, 12th, and 14th aspects, wherein the constituent material particle is made of an electrically conductive material and, when baked, forms an electrode of the pattern.
According to a 18th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 11th or 14th aspect, wherein when the pattern-forming material particle is electrically charged and thereafter jetted out by electrostatic force so as to be deposited onto the surface of the panel substrate, by which the pattern is formed:
baking the pattern-forming material particles containing different kinds of constituent material particles which are deposited so as to be coexistent at individual sites, by which different constituent material particles are mixed together.
According to a 19th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 11th or 14th aspect, wherein when the pattern-forming material particle is electrically charged and thereafter jetted out by electrostatic force so as to be deposited onto the surface of the panel substrate, by which the pattern is formed:
stacking the pattern-forming material particles on the panel substrate into a plurality of layers; and
changing the kind of constituent material particles contained in the pattern-forming material particles among the individual layers of the pattern-forming material particles.
According to a 20th aspect of the present invention, there is provided a method for forming a pattern on a surface of a panel substrate according to the 11th or 14th aspect, wherein when the pattern-forming material particle is electrically charged and thereafter jetted out by electrostatic force so as to be deposited onto the surface of the panel substrate, by which the pattern is formed:
stacking the pattern-forming material particles on the panel substrate into a plurality of layers; and
depositing the pattern-forming material particles in a wide-bottom shape with the lower layers, or layers closer to the panel substrate, increasingly wider in width.
According to a 21st aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first aspect, wherein when the pattern is formed onto the surface of the panel substrate by the jetted-out pattern-forming material particles,
an electrostatic pattern is formed on an intermediate body, the pattern-forming material particles are deposited onto the electrostatic pattern formed on the intermediate body, the pattern-forming material particles deposited on the intermediate body are transferred onto the panel substrate, and thereafter the transferred pattern-forming material particles are fixed onto the panel substrate; and
further comprising cleaning the intermediate body onto which the pattern-forming material particles have been transferred, by which remaining pattern-forming material particles are removed.
According to a 22nd aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the 21st aspect, wherein when the transferred pattern-forming material particles are fixed onto the panel substrate, the processes from the charging of the pattern-forming material particles to the removal of pattern-forming material particles remaining on the intermediate body are repeated a plurality of times, by which a plurality of pattern-forming material particles are fixed; and
further comprising baking the panel substrate so that the pattern is formed on the panel substrate, by which a plurality of patterns are formed at a time.
According to a 23rd aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the 21st or 22nd aspect, wherein
the intermediate body is one in which an electrical conductor is buried within a platy substrate along the pattern, and
in forming the electrostatic pattern on the intermediate body, a voltage is applied to the electrical conductor, by which the electrostatic pattern is formed on the surface of the substrate as the intermediate body.
According to a 24th aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the 21st or 22nd aspect, wherein the intermediate body is one in which a patterned mask is provided on the surface of the platy substrate.
According to a 25th aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or 21st aspect, wherein when the pattern-forming material particles are electrically charged, the pattern-forming material particles are electrically charged by an electric charger.
According to a 26th aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or 21st aspect, wherein when the electrically charged pattern-forming material particles are jetted out by electrostatic force, a mixture of the pattern-forming material particles and highly chargeable particles are jetted out.
According to a 27th aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or 21st aspect, wherein when the pattern-forming material particles are electrically charged the pattern-forming material particles are mixed with highly chargeable particles to be electrically charged.
According to a 28th aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first or 21st aspect, wherein when the pattern-forming material particles are electrically charged, the pattern-forming material particles are electrically charged by friction between a blade and the pattern-forming material particles.
According to a 29th aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first aspect, wherein when the electrically charged pattern-forming material particles are jetted out through the nozzle by exerting electrostatic force on the electrically charged pattern-forming material particles to perform application of the pattern-forming material particles; and
when the pattern is formed by the jetted-out pattern-forming material particles, a voltage is applied to an electrically conductive layer present on a top surface of the panel.
According to a 30th aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first aspect, wherein when the electrically charged pattern-forming material particles are jetted out through the nozzle by exerting electrostatic force on the electrically charged pattern-forming material particles to perform application of the pattern-forming material particles; and
when the pattern is formed by the jetted-out pattern-forming material particles, a voltage is applied to a conductor provided on a back side of the panel; and
fixing the pattern on the panel substrate.
According to a 31st aspect of the present invention, there is provided a method for forming a pattern onto a panel substrate according to the first aspect, wherein when the electrically charged pattern-forming material particles are jetted out through the nozzle by exerting electrostatic force on the electrically charged pattern-forming material particles to perform application of the pattern-forming material particles; and
when the pattern is formed by the jetted-out pattern-forming material particles, a voltage is applied to a conductor provided on a back side of the panel, an electrically conductive film is formed on a top surface of the panel, and a voltage is applied to the film.